1. Evaluation of Proposed FDA Criteria for Evaluation of Radiolabeled Red Cell Recovery Trials Larry J. Dumont, MBA, PhD James P. AuBuchon, MD for the Biomedical Excellence for Safer Transfusion (BEST) Collaborative BESTBEST Blood Products Advisory Committee Rockville, MD May 1, 2008 TRANSFUSION online: 22-Feb-2008 doi: 10.1111/j.1537-2995.2008.01642.x.

2. Conflicts of Interest Consultant –Gambro BCT –bioMérieux –BCSI –Verax Biomedical Research support DHMC –Cerus –Fenwal –Gambro BCT –Haemonetics –Immunetics –Navigant Biotechnologies –Verax Biomedical Travel Support –FDA

3. FDA - RBC Performance Criteria 1.In vitro – e.g., hemolysis and ATP 2.In vivo - autologous 24 hour recovery 3.In vivo - clinical outcome (safety trials)

4. FDA - RBC Performance Criteria 1.In vitro – e.g., hemolysis and ATP 2.In vivo - autologous 24 hour recovery 3.In vivo - clinical outcome (safety trials)

5. Background: FDA Requirements Mean 24h recovery ≥ 70% (Ross et al. JCI 1947;26:687-703) Mean 24h recovery ≥ 75% (FDA Workshop, April 25, 1985) Mean 24h recovery ≥ 75% -and- SD  9% (FDA 1998)

6. FDA Requirements Mean recovery  75% - and – SD  9% - and – LCL 95% for population proportion of successes (  75%) > 70% BPAC, July, 2004 “Success Threshold”  21 successes out of 24  18 successes out of 20

7. % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % % CAUTION IT WILL BE OK

8. Radiolabeled Red Cell Recovery – circa 1970 OK

9. Radiolabeled Red Cell Recovery – circa 1985 OK

10. Radiolabeled Red Cell Recovery – circa late 1990s OK min & max

11. Radiolabeled Red Cell Recovery – circa 2004 Individual recoveries < 75% are FAILURES

12. Implication Test RBC must have  90.3% “success” for an 80% chance of passing an in vivo recovery trial 1.What is the clinical evidence? 2.What is the capability of current RBC products?

13. Our Conclusion after review of the evidence A success threshold of 67-70% will provide a reasonable probability of passing the FDA- proposed criteria for RBC products in current use in the United States

14. Objective Define the ability of currently available Red Blood Cell (RBC) collection and storage systems to satisfy new RBC in vivo recovery criteria proposed by the FDA for approval of RBC systems.

15. Study 9987 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … Study 7985 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … Study 345 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … Study 134 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … Study 12345 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … ● ● ● LAB 11 Study 9987 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … Study 7985 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … Study 345 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … Study 134 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … Study 12345 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … ● ● ● LAB 2 ● ● ● Central Database Data verification by Sponsors n=12 Data review and cleaning Methods ● ● ● Study 9987 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … Study 7985 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … Study 345 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … Study 134 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … Study 12345 24h Recovery CONTROL TEST 78.2% 80.3% 82.1 79.4 80.7 77.3 … … ● ● ● LAB 1 Approved/cleared methods 1990-2006

16. Liquid Stored (42 days) Central Database Sample with replacement n=24 N=5000 Methods Gamma Irradiated (28 days post) Frozen, deglycerolized (15-30 days) Sample with replacement n=24 N=5000 Sample with replacement n=24 N=5000 FDA/CBER

17. Evaluable RBC Recoveries 1990 - 2006 n=34 studiesLeukocyte- reduced Non-leukoctye- reduced Automated Collection Liquid stored2059214 Gamma Irradiated670 subtotal2729281 Manual Collection Liquid stored291136427 Gamma Irradiated243256 subtotal315168483 Frozen14037177 TOTAL727214941

18. NMin5%MedianFrequency of Recovery < 75% Frequency of Recovery < 70% Frequency of Recovery < 67% MeanSD 6413670.782.411.7%4.5%1.9%82.1%6.71% BINOMIAL EXPANSION N=24 Probability (Number of successes ≥ 21 ) 0.693

19. BINOMIAL EXPANSION N=24 Probability (Number of successes ≥ 21 ) 0.035 NMin5%MedianFrequency of Recovery < 75% Frequency of Recovery < 70% Frequency of Recovery < 67% Mean (%) SD (%) 12347.163.679.330.9%18.7%8.9%77.9%8.36%

20. NMin5%MedianFrequency of Recovery < 75% Frequency of Recovery < 70% Frequency of Recovery < 67% MeanSD 17752.274.288.05.6%2.8%1.2%86.6%7.41% BINOMIAL EXPANSION N=24 Probability (Number of successes ≥ 21 ) 0.957

21. One Sample Replicate LAB ASC Rec <70% 257 1 1 64.20 1 257 1 1 71.60 0 257 1 1 70.20 0 257 1 1 79.30 0 257 1 1 76.70 0 257 1 1 93.50 0 257 1 1 73.40 0 257 1 1 85.53 0 257 1 1 71.14 0 257 2 1 81.04 0 257 2 1 66.85 1 257 2 1 77.13 0 257 2 1 84.04 0 257 2 1 81.85 0 257 2 1 77.68 0 257 2 1 80.49 0 257 2 1 58.09 1 257 2 1 82.71 0 257 2 3 40.32 1 257 2 3 83.42 0 257 2 3 75.44 0 257 2 5 73.69 0 257 2 5 74.95 0 257 2 5 74.26 0 Mean=74.9 X SD=10.5 X 4/24 < 70% X 67%, 70%, 75%

22. Number of successes (75%) ≥ 21= 67.3% Mean ≥ 75%= 100% SD ≤9%= 95.2% RESAMPLING n=24; N=5000 Failures

23. RESAMPLING n=24; N=5000 Number of successes (75%) ≥ 21= 3.5% Mean ≥ 75%= 95.5% SD ≤9%= 71.4% Failures

24. RESAMPLING n=24; N=5000 Number of successes (75%) ≥ 21= 95.4% Mean ≥ 75%= 100% SD ≤9%= 83.9% Failures

25. Preliminary Conclusion FDA-proposed success threshold of >75% for individual recovery is unacceptable The general clinical performance for these products is adequate as proved over years of clinical practice, and certainly represents the state-of-the-art

26. Sensitivity to Success Threshold n=24

27. Chance of current, state-of-the-art RBC products passing FDA-proposed criteria RBCMean ≥ 75% SD ≤9% Success: Recovery > 75% Success: Recovery > 70% Success: Recovery > 67% 42d Liquid Stored 100%95.2%69.3% (58%)* 97.9% (94%)* 99.9% (99%) Gamma95.5%71.4%3.5% (3.0%)* 31.8% (25%)* 84.0% (74%)* Frozen100%83.7%95.7% (90%)* 99.6% (98%)* 100% (99%)* * ≥ 18 successes out of 20 trials

28. Other Key Observations Current RBC components are not different than the study population There are differences between laboratories and/or study subjects

29. 4 of 36 < 75% (11%) 1 of 36 < 70% (2.8%) < 75% 11.7% < 70% 4.5% Current Methods are not different than the study population

30. There are differences between laboratories and/or study subjects

31. Conclusions The FDA-proposed success threshold of >75% is not validated against currently approved RBC products available in the US Based on actual in vivo recovery performance, a success threshold of 67-70% will provide a reasonable probability of passing the FDA- proposed criteria LCL 95% for population proportion of successes (  67%) > 70% The mean and SD criteria may be applied as general guidance, but used with caution as distributions do not meet normality assumptions.

32. Our Conclusion after review of the evidence 1.A success threshold of 67-70% will provide a reasonable probability of passing the FDA-proposed criteria for RBC products in current use in the United States 2.We should not make it unnecessarily burdensome for new innovations to enter the market

33. Acknowledgements Study Laboratories American Red Cross, Louisville, KY Blood Center of Wisconsin, Milwaukee, WI Dartmouth-Hitchcock Medical Center, Lebanon, NH Hoxworth Blood Center, Cincinnati, OH Mayo Clinic, Rochester, NY American Red Cross, Norfolk, VA University of North Carolina, Chapel Hill, NC University of New Mexico, Albuquerque, NM University of Virginia, Charlottesville, VA Walter Reed Army Institute of Research Yale University, New Haven, CN Study Sponsors American Red Cross Baxter Baxter/Army Cutter / Pall Gambro BCT, Inc. Haemonetics / Transfusion Technologies Hemasure MacoPharma / UnitedPharma Terumo Vitex Individuals Lauren Clark Jaime Houghton Sherrie Sawyer Jose A. CancelasMike McAteer Yariv Sivan Tammy Corda Jeff Miripol Edward Snyder M. Dean Elfath Ed Nelson Tania VandenBroeke John Hess Leslie Rose Pamela Whitley Stein Holme Neeta Rugg